It is known to manufacture activated form coke from pretreated black coal material in the form of a granulate or a particulate product, the black coal being powdered and made into a paste with a binder and transformed into granulates which are subsequently pyrolyzed and activated, thereby yielding a corresponding particulate or granulated product.
When pretreating the black coal it is possible in addition to precede the powdering by a de-ashing or extraction or oxidation step.
Known binders for converting the powdered black coal into a paste include, black coal tar and wood tar, inorganic gels such as silica gel and iron or aluminum hydroxide, optionally in combination with neutralizing substances such as caustic soda or lime.
It is also known for the manufacture of activated coke to convey the pretreated products intended for that purpose through a shaft which comprises the aforementioned various treatment zones, in which the pyrolysis, heating and activating takes place by laterally introduced and discharged gases or vapors.
In the known process, the material to be treated and which is conveyed through the shaft is rerouted repeatedly in opposite directions in the form of a column of material for the attainment of increased reaction areas and an effective mixing of the reagents, the gases or vapours passing therethrough in a direction transversely to the columns.
In another embodiment the material to be treated is passed through sleeve-shaped internal structures overlapping each other and centrally passing through the shaft from the top downwards and the material column is subjected to a flow therethrough of the treatment gases which are introduced sideways.
The known processes for attaining the required thermal and material exchange require relatively long residence periods the individual zones, in particularly if the flow through the column of material proceeds vertically whereby the energy consumption for effecting the flow and for transferring the heat is increased.
Moreover, an uneven treatment of the material particles contained in the material column results from the pronounced flow profile.
Finally, substantial abrasion losses take place even during the manufacture of the activated coke, because the material particles in the lower region of the material column are subjected to the static pressure of the material load and accordingly high frictional forces in relation to adjoining material particles or the internal structures in the shaft are unavoidable.